Bone grafting of maxillary alveolus cleft defect followed by insertion of dental implant may be a good alternative to conventional prosthetic treatment. The principle is the formation of stable alveolar crest with a sufficient three-dimensional volume. The problems are lack and quality of mucoperiosteum for the reconstruction of shell and bone gap characteristics for bone graft intake. The procedure was carried out by a single surgeon (MD) in 45 patients between 29 August 2001 and 30 June 2006, with an 86.7% success rate. The success was defined as completed process with dental implant insertion and its loading by a prosthetic suprastructure without a failure for at least 15 months from that last step. The success rate mainly depends on 1) good alveolar arch flow of maxilla segments in both horizontal and vertical planes; 2) the height of osseous poles of at least 12 mm and onlay augmentation of built-up section does not work; 3) adequate volume of cancellous bone graft, 3.7 cm on average. On the basis of histologic verification and clinical findings, the bone graft is matured enough to ensure a primary stability of a fixture in 12.5 weeks after reconstruction. Early load may prevent bone resorption. Prediction of complications are as follows: 1) graft resorption increases according to gap size and low possibility of revascularization; 2) a higher number of complications are linked to presence of oronasal fistula and to scarring of soft tissues; 3) because of more gracile skeleton and female metabolism, the risk is higher in women.